Shoe

ABSTRACT

A shoe includes a sole, an upper portion disposed above the sole and surrounding a foot insertion part, and a buffer including a lower surface and accommodated within the foot insertion part. The lower surface of the buffer includes a projection part projecting toward a facing surface that faces the lower surface, a recess part adjacent to the projection part and recessed from the projection part toward the upper portion, and a circumferential edge projection part projecting, around the recess part, toward the facing surface side with respect to the projection part. When the buffer receives a predetermined first load, the circumferential edge projection part contacts the facing surface whereas the projection part has no contact with the facing surface, and when the buffer receives a predetermined second load, which is larger than the first load, the circumferential edge projection part and the projection part contact the facing surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage application of International Application No. PCT/JP2019/024895, filed Jun. 24, 2019, the contents of which are hereby incorporated herein by reference.

BACKGROUND Field of the Invention

The present invention relates to a shoe.

Background Information

A shoe that includes a buffer member, such as a midsole, provided between the upper portion and the sole is known. For example, U.S. Pat. No. 9,737,109 describes footwear having a removable outsole, midsole, and upper portion. On the bottom surface of the midsole of the footwear, multiple protrusions are provided to mate with pockets on the outsole. The protrusions are separated by slots to mate with raised walls provided in the pockets. Also, the footwear is configured to be customized for each user by swapping the midsole, for example.

SUMMARY

With regard to a shoe that includes a buffer member, it has been determined that to make a shoe feel smooth for a foot during insertion thereof into the shoe and ensure comfort, it is desirable to employ a softer buffer member to increase the displacement of the buffer member caused by a load received from the foot (hereinafter, simply referred to as a “load”). However, if the displacement of the buffer member caused by a load is increased, a change in the foot position within the shoe can increase under high load, such as during running, so that the stability and fit may degrade.

Meanwhile, to improve the stability under high load, if the displacement of the buffer member caused by a load is decreased, the buffer member feels less smooth for the foot, which is disadvantageous in terms of the comfort.

The footwear described in U.S. Pat. No. 9,737,109 is configured such that the midsole can be replaced to ensure the comfort according to the user's preference. However, with a single midsole, different properties cannot be obtained. Therefore, it has been determined that there is room for improvement in conventional footwear, in terms of obtaining both the comfort and the stability with balance.

The present disclosure has been made in view of such an issue, and a purpose thereof is to disclose embodiments of a shoe that can provide both comfort and stability with balance.

In response to the above issue, a shoe according to one embodiment includes a sole, an upper portion provided above the sole to surround a foot insertion part, and a buffer member accommodated within the foot insertion part. The lower surface of the buffer member can include a projection part projecting toward a facing surface that faces the lower surface, a recess part formed adjacent to the projection part and recessed from the projection part toward the upper portion, and a circumferential edge projection part projecting, around the recess part, toward the facing surface side with respect to the projection part. When the buffer member receives a certain first load, the circumferential edge projection part contacts the facing surface while the projection part has no contact with the facing surface. When the buffer member receives a certain second load, which is larger than the first load, the circumferential edge projection part and the projection part contacts the facing surface.

Optional combinations of the above, and implementation of embodiments of the present invention, including the constituting elements and expressions, in the form of methods, apparatuses, programs, transitory or non-transitory storage medium storing programs, or systems can also be practiced as additional modes of the present invention.

Embodiments of the present invention provide a shoe that can provide both the comfort and the stability with balance.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view that schematically illustrates a shoe according to a first embodiment of the present invention;

FIG. 2 is a plan view of a buffer member of the shoe shown in FIG. 1;

FIG. 3 is a side view of the buffer member shown in FIG. 2;

FIG. 4 is a bottom view of the buffer member shown in FIG. 2;

FIG. 5 is a graph that shows relationships between the load and the displacement of the buffer member shown in FIG. 2;

FIG. 6 is a longitudinal sectional view of the buffer member shown in FIG. 2 taken along line A-A;

FIG. 7 is another longitudinal sectional view of the buffer member shown in FIG. 2 taken along line A-A;

FIG. 8 is a plan view that illustrates contours of the buffer member shown in FIG. 2 and the upper portion;

FIG. 9 is a plan view that illustrates a change in the contour of the buffer member shown in FIG. 2;

FIG. 10 is another graph that shows relationships between the load and the displacement of the buffer member shown in FIG. 2;

FIG. 11 is a sectional view of a buffer member including a deformation restricting unit, taken along line A-A;

FIG. 12 is a sectional view of a buffer member including another deformation restricting unit, taken along line A-A;

FIG. 13 is a sectional view, taken along line A-A, of a buffer member of which the widths of the medial side and the lateral side of a body part are different;

FIG. 14 is a sectional view, taken along line A-A, of a buffer member of which the friction coefficients of the medial side and the lateral side of the body part are different;

FIG. 15 is a perspective view that schematically illustrates a shoe according to a second embodiment of the present invention;

FIG. 16 is a side view of the shoe shown in FIG. 15;

FIG. 17 is a plan view of the shoe shown in FIG. 15;

FIG. 18 is a sectional view of the shoe shown in FIG. 15 taken along line B-B;

FIG. 19 is a side view that illustrates another example of the shape of a link member in the shoe shown in FIG. 15;

FIG. 20 is a side view that illustrates yet another example of the shape of the link member in the shoe shown in FIG. 15;

FIG. 21 is a plan view of the buffer member according to a first modification;

FIG. 22 is a plan view that illustrates a first exemplary shape of the buffer member according to a modification;

FIG. 23 is a plan view that illustrates a second exemplary shape of the buffer member according to a modification;

FIG. 24 is a plan view that illustrates a third exemplary shape of the buffer member according to a modification;

FIG. 25 is a plan view that illustrates a fourth exemplary shape of the buffer member according to a modification;

FIG. 26 is a longitudinal sectional view of the buffer member according to a modification, taken along line A-A;

FIG. 27 is another longitudinal sectional view of the buffer member shown in FIG. 26, taken along line A-A; and

FIG. 28 is a sectional view of a shoe according to a modification, taken along line B-B.

DETAILED DESCRIPTION

In the following, the present invention will be described based on preferred embodiments with reference to each drawing. In the embodiments and modifications, like reference characters denote like or corresponding constituting elements and members, and the same description will be omitted as appropriate. Also, the dimensions of a member can be appropriately enlarged or reduced in each drawing in order to facilitate understanding. Further, in each drawing, part of a member less important in describing embodiments can be omitted.

Also, terms including ordinal numbers, such as “first” and “second”, are used to describe various constituting elements; however, such terms are used in order to distinguish one constituting element from another and do not limit the constituting elements.

First Embodiment

In the following, a configuration of a shoe 100 according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view that schematically illustrates the shoe 100 according to the first embodiment. Each drawing mentioned below, including FIG. 1, illustrates a shoe for a right foot, unless otherwise specified. However, the description in the present specification is also applicable to a shoe for a left foot. Also, in each drawing mentioned below, illustration of a shoelace is omitted.

The shoe 100 of the present embodiment can be used for walking shoes, running shoes, safety shoes, and sports shoes for tennis or basketball, for example, and the use of the shoe 100 is not limited. The shoe 100 includes a sole 10, an upper portion 20, and a buffer member 30. The sole 10 is a portion to be in contact with the ground. The upper portion 20 includes a foot insertion part 20 a that surrounds an internal space for accommodating a foot. The upper portion 20 is fixed above the sole 10 by bonding or the like. The buffer member 30 is accommodated within the foot insertion part 20 a. These will be detailed below.

Upper Portion

A direction extending along a center line La with respect to a width direction of the upper portion 20 will be referred to as a “longitudinal direction”, as shown in FIG. 1. Accordingly, a width direction is perpendicular to the center line La. The direction toward the toe side along the center line La will be referred to as the “front side” or “front”, and the opposite direction will be referred to as the “rear side” or “rear”. Also, the direction from the lateral side toward the medial side of the foot along a width direction will be referred to as the “inner side” or “inward”, and the opposite direction will be referred to as the “outer side” or “outward”. In a state where the shoe 100 is placed on a horizontal plane (hereinafter, referred to as a “horizontal state”), the upper portion side will be referred to as the “upper side” or “above”, and the opposite side will be referred to as the “lower side” or “below”. Also, in a horizontal state, a direction extending vertically will be referred to as a “vertical direction”.

Also, in the upper portion 20, a portion corresponding to the metatarsal bones with respect to a longitudinal direction will be referred to as a midfoot portion. Also, in the upper portion 20, a portion in front of the midfoot portion in a longitudinal direction will be referred to as a forefoot portion, and a portion in the rear of the midfoot portion in a longitudinal direction will be referred to as a rearfoot portion. The forefoot portion is a portion that almost corresponds to the phalanges, and the rearfoot portion is a portion that almost corresponds to the tarsals. When the longitudinal length of the shoe 100 is regarded as 100%, the midfoot portion almost corresponds to a region from 30% to 80% from the tip, occupying a range parallel with a straight line perpendicular to the center line La. Similarly, the forefoot portion almost corresponds to a region from 0% to 30% from the tip, and the rearfoot portion almost corresponds to a region from 80% to 100% from the tip.

On the rear side of the upper portion 20, a wearing opening 20 b through which a foot is inserted is provided. In a region of the upper portion 20 in front of the wearing opening 20 b, a central opening 20 c is provided. Along the edge of the central opening 20 c of the upper portion 20, grommets 20 h are provided such that a shoelace passes therethrough. Inside the central opening 20 c, a shoe tongue 70 is provided. The central opening 20 c is not an essential configuration, and the upper portion 20 can have a so-called monosock structure. Also, including the grommets 20 h and the shoe tongue 70 is not essential.

Buffer Member

The buffer member 30 will be described. The buffer member 30 is formed of a flexible material and, when a wearer wears the shoe 100, the buffer member 30 intervenes between the foot and the sole 10 to cushion the impact applied to the foot. The buffer member 30 functions as an insole. FIG. 2 is a plan view of the buffer member 30. FIG. 3 is a side view of the buffer member 30. FIG. 4 is a bottom view of the buffer member 30.

In terms of providing both the comfort and the stability with balance, the buffer member 30 has been considered and the following findings have been obtained. FIG. 5 is a graph that shows relationships between the load and the displacement of the buffer member 30. In this graph, the horizontal axis represents displacement D, and the vertical axis represents a load F. The scale on each of the horizontal axis and the vertical axis represents relative levels with respect to a predetermined reference value. Each of the graph g1 and graph g2 shows the load F with respect to the displacement D (hereinafter, referred to as a “displacement gradient”). The graph g1 illustrates a case where the displacement gradient is larger than that of the graph g2, i.e., the buffer member 30 is softer. The graph g2 illustrates a case where the displacement gradient is smaller than that of the graph g1, i.e., the buffer member 30 is harder.

To improve smoothness for a foot during insertion thereof, it is desirable that the displacement gradient is large and the buffer member 30 is soft, as shown in the graph g1. However, when the displacement gradient is large, the displacement D becomes excessive under high load, such as during running, which degrades the stability and durability. Accordingly, under high load, it is desirable that the displacement gradient is small and the buffer member 30 is hard, as shown in the graph g2. Considering the above, a configuration has been conceived in which the displacement gradient changes according to the magnitude of the load F received by the buffer member 30 (see the graph g3). Also, it is found that, by making the contact area larger between the buffer member 30 and a facing surface 16, which faces the lower surface of the buffer member 30, when the load F is large, the displacement gradient changes. In the following, a configuration example for achieving the properties shown in the graph g3 will be described.

The description returns to FIGS. 2-4. As illustrated in FIGS. 2 and 3, on a top surface 30 e of the buffer member 30, edge protruding parts 30 h and 30 j are provided. The edge protruding parts 30 h and 30 j protrude from the top surface 30 e such as to surround the vicinity of the heel, from the medial side to the lateral side. The top line of the edge protruding part 30 h on the medial side is positioned higher than the top line of the edge protruding part 30 j on the lateral side. Alternatively, the top line of the edge protruding part 30 j can be positioned higher than the top line of the edge protruding part 30 h.

As illustrated in FIG. 4, on a lower surface 30 b of the buffer member 30, a projection part 32, a recess part 34, and a circumferential edge projection part 36 are provided. The projection part 32 projects toward the facing surface 16 that faces the lower surface 30 b. In the present embodiment, the facing surface 16 is exemplified by a top surface 10 b of the sole 10. When an insole or the like intervenes between the sole 10 and the buffer member 30, the facing surface 16 corresponds to the top surface of the insole or the like.

The arrangement of the projection part 32 is not particularly limited, and the projection part 32 in the present embodiment is disposed at a position corresponding to the heel. The shape of the projection part 32 is also not particularly limited, and the projection part 32 in the present embodiment is an insular portion having a planar shape of an ellipse of which the longitudinal dimension is larger than the width dimension. Ellipses in the present disclosure include, in addition to an ellipse, a shape similar to an ellipse, such as an oval. The recess part 34 is formed adjacent to the projection part 32 and recessed from the projection part 32 toward the upper portion 20 side. In a width direction, the recess part 34 intervenes between the projection part 32 and the circumferential edge projection part 36. The recess part 34 in the present embodiment is circumferentially formed to surround the projection part 32 in plan view. The circumferential edge projection part 36 projects, around the recess part 34, toward the facing surface 16 side with respect to the projection part 32.

In the present embodiment, to change the displacement gradient, the contact area between the buffer member 30 and the facing surface 16 (top surface 10 b) is made to change according to the load F. More specifically, when the buffer member 30 receives a predetermined first load F1 (low load), the circumferential edge projection part 36 contacts the facing surface 16 whereas the projection part 32 has no contact with the facing surface 16; when the buffer member 30 receives a predetermined second load F2 (high load), both the circumferential edge projection part 36 and the projection part 32 contacts the facing surface 16. When the projection part 32 contacts the facing surface 16, the contact area increases accordingly and the load F per unit area decreases, so that the displacement gradient changes.

For example, the first load F1 can be set based on a load F that the buffer member 30 receives from a foot when the foot is inserted into the shoe or during slow walking. The second load F2 can be set based on a load F that the buffer member 30 receives from a foot during running. The second load F2 is larger than the first load F1.

FIGS. 6 and 7 are also referred to. Each of FIGS. 6 and 7 is a longitudinal sectional view of the buffer member 30 taken along line A-A and shows a cross section in the middle in a longitudinal direction of the projection part 32. FIG. 6 shows a state where the buffer member 30 receives the first load F1, and FIG. 7 shows a state where the buffer member 30 receives the second load F2. In the present embodiment, the buffer member 30 is not bonded to the facing surface 16 and is movable within the foot insertion part 20 a. Accordingly, upon reception of the load F, the buffer member 30 is deformed in a width direction, so that the dimension in a width direction of the buffer member 30 increases.

In the case of the low load shown in FIG. 6, the circumferential edge projection part 36 contacts the facing surface 16, and a lower surface 32 d of the projection part 32 is spaced away upward from the facing surface 16, with a space S32 formed in between. When the load F increases from the state shown in FIG. 6, the circumferential edge projection part 36 is deformed to expand in a width direction while contacting the facing surface 16. Concurrently, the projection part 32 moves downward, and the space S32 gradually decreases with the load F increasing; when the load F exceeds a threshold, the space S32 disappears. At that time, the lower surface 32 d of the projection part 32 contacts the facing surface 16, and the projection part 32 is deformed so as to vertically collapse. As the load F further increases, the contact area between the lower surface of the projection part 32 and the facing surface 16 increases, so that the state reaches that shown in FIG. 7. Thus, in the case of the high load as shown in FIG. 7, the contact area between the buffer member 30 and the facing surface 16 increases and the load F per unit area decreases, so that the displacement gradient decreases, compared to the case of the low load shown in FIG. 6.

When the longitudinal dimension of the projection part 32 is smaller, a longitudinal range in which the displacement gradient can be changed is narrower. Accordingly, the longitudinal dimension of the projection part 32 is desirably large. Therefore, the projection part 32 in the present embodiment has a planar shape of an ellipse of which the longitudinal dimension is larger than the width dimension.

The circumferential edge projection part 36 can be configured to have no contact with the facing surface 16 in a no-load state in which a foot is not inserted. However, in the present embodiment, the circumferential edge projection part 36 is configured to contact the facing surface 16 also in a no-load state.

It is desirable that the projection part 32 can move downward smoothly from a low load state to a high load state. Accordingly, the buffer member 30 in the present embodiment includes a body part 35 that includes the circumferential edge projection part 36, and a movable part 33 that includes the projection part 32. Providing the body part 35 and the movable part 33 separately can facilitate moving of the projection part 32.

The body part 35 has an outer shape extending along the foot insertion part 20 a in plan view (see also FIGS. 2 and 3). In a middle part in a width direction of the body part 35, an accommodation part 37 is provided to accommodate at least part of the movable part 33. The accommodation part 37 in the present embodiment has a shape that can accommodate substantially the entire movable part 33. The accommodation part 37 in this example has a planar shape of an ellipse of which the longitudinal dimension is larger than the width dimension. In the present embodiment, to make the movable part 33 move gently, an inner circumferential surface 37 j of the accommodation part 37 is formed into a tapered shape of which the lower side is narrower. When a downward load F is applied to the buffer member 30, the movable part 33 slides within the accommodation part 37 of the body part 35 to move downward. The accommodation part 37 includes an opening part 37 h provided in a middle part in a width direction of the body part 35.

An outer circumferential surface 33 e of the movable part 33 has a shape corresponding to the inner circumferential surface 37 j. In other words, the outer circumferential surface 33 e of the movable part 33 has a planar shape of an ellipse of which the longitudinal dimension is larger than the width dimension. The outer circumferential surface 33 e of the movable part 33 has a truncated elliptical cone shape along the inner circumferential surface 37 j. As illustrated in FIG. 6, the vertical dimension of the movable part 33 is smaller than that of the circumferential edge projection part 36, and the movable part 33 has a size such that it hangs, at the outer circumferential surface 33 e, on the accommodation part 37.

There will now be described a planar shape of the buffer member 30. FIG. 8 is a plan view that shows a relationship between a peripheral wall surface 30 p of the buffer member 30 and the foot insertion part 20 a of the upper portion 20. The peripheral wall surface 30 p is a side surface extending along the outer circumference of the buffer member 30. If the width of the buffer member 30 is too large, insertion of the buffer member 30 into the upper portion 20 will be difficult. Accordingly, a space S1 in a width direction between the peripheral wall surface 30 p of the buffer member 30 and the foot insertion part 20 a of the upper portion 20 is larger than a space S2 in a longitudinal direction between the buffer member 30 and the upper portion 20. The space S1 is the sum of a space S1(a) and a space S1(b) on both sides in a width direction, and the space S2 is the sum of a space S2(a) and a space S2(b) on both sides in a longitudinal direction.

Extension in a planar direction of the buffer member 30 will be described. FIG. 9 is a plan view that shows a planar contour of the buffer member 30 receiving a load. In FIG. 9, a planar contour of the buffer member 30 in a no-load state is indicated by a dotted line, and a planar contour receiving the second load F2 is indicated by a solid line. To distribute the load F in a width direction, the buffer member 30 in the present embodiment is configured such that extension E1 in a width direction of the buffer member 30 receiving the load F becomes larger than extension E2 in a longitudinal direction thereof. The extension E1 is the sum of extension E1 (a) and extension E1 (b) on both sides in a width direction, and the extension E2 is the sum of extension E2(a) and extension E2(b) on both sides in a longitudinal direction.

FIGS. 6 and 7 are now referred to. The body part 35 and the movable part 33 can be formed of various materials having desired properties. For example, the body part 35 can be formed of resin foam, such as ethylene-vinyl acetate copolymer (EVA) resin and thermoplastic polyurethane (TPU) resin. The movable part 33 can be formed of the same material as the body part 35 or can be formed of a different material. Each of the body part 35 and the movable part 33 can include a single member or can includes multiple members. Also, the body part 35 and the movable part 33 can be separate bodies, or a foam material having different hardness, such as a GEL material, can be disposed inside or on a surface. In this case, smoothness for a foot or cushioning properties can be changed.

The hardness of the buffer member 30 will be described. The hardness of the material of the body part 35 and the hardness of the material of the movable part 33 can be the same or can be different. In the present embodiment, the hardness of the material of the movable part 33 is higher than the hardness of the material of the body part 35. With the softer body part 35, the shoe feels smooth for a foot under low load, and, with the harder movable part 33, high rigidity can be obtained and the stability can be ensured easily under high load. When the area occupied by the movable part 33 is large, the movable part 33 can be formed softer than the body part 35 in order to obtain the cushioning properties. Also, to obtain a desired property, the body part 35 can be formed harder than the movable part 33.

The hardness of the material of the body part 35 can be entirely uniform or can be partially different. Particularly, a portion 35 e and a portion 35 j of the body part 35 located respectively on the lateral side and the medial side with respect to the movable part 33 can be formed of materials having different hardness. In the present embodiment, the hardness of the material of the portion 35 j on the medial side is higher than the hardness of the material of the portion 35 e on the lateral side. When a high load is applied to the medial side during exercise, deformation can be restrained, so that the stability can be ensured easily. When the shoe is employed as a shoe used for a sport played in a court in which a load is applied to the lateral side of the shoe, for example, the portion 35 e can be harder than the portion 35 j.

Deformation Restricting Unit

With reference to FIGS. 10-12, a deformation restricting unit (deformation restrictor) 18 will be described. When the buffer member 30 is excessively deformed upon reception of a high load, the stability may be degraded. Accordingly, in the present embodiment, the deformation restricting unit 18 restricts a predetermined amount or more of deformation of the buffer member 30.

FIG. 10 is a graph that shows relationships between the load F and the displacement D of the buffer member 30 when the deformation restricting unit 18 is provided and that corresponds to FIG. 5. In FIG. 10, the graph g3 shows a case where the deformation restricting unit 18 is not provided, and the graph g4 shows a case where the deformation restricting unit 18 is provided. When the deformation restricting unit 18 is provided and when the load exceeds a third load F3, the displacement D is restrained, so that the displacement gradient becomes smaller. The third load F3 is set higher than the second load F2, and the displacement gradient changes at three stages according to the load F. In this configuration, the stability in the region where the load F is the third load F3 or higher can be ensured. The third load F3 can be set based on a load F that the buffer member 30 receives from a foot during especially high-intensity exercise.

The configuration of the deformation restricting unit 18 is not particularly limited. For example, the deformation restricting unit 18 can be disposed on a part that faces the lower surface 30 b or the peripheral wall surface 30 p of the buffer member 30. FIG. 11 is a sectional view of the buffer member 30 including the deformation restricting unit 18 taken along line A-A and corresponds to FIG. 6. FIG. 11 shows a state where the third load F3 is applied. In the example of FIG. 11, the deformation restricting unit 18 includes a protruding part 16 p that protrudes from the facing surface 16, and an abutting part 36 m provided on the buffer member 30. The abutting part 36 m in this example is an inner wall in a width direction of a lower surface recess part 36 d provided on the lower surface 30 b of the buffer member 30 (the lower surface of the circumferential edge projection part 36). When the buffer member 30 receives the third load F3, the abutting part 36 m abuts onto the protruding part 16 p, so that deformation in a width direction of the circumferential edge projection part 36 is restricted.

FIG. 12 is a sectional view of the buffer member including another deformation restricting unit 18 taken along line A-A and corresponds to FIG. 11. In the example of FIG. 12, the abutting part 36 m is provided on a side surface of the circumferential edge projection part 36 (the peripheral wall surface 30 p of the buffer member 30), and the protruding part 16 p is positioned off the lower surface 30 b of the buffer member 30 (the lower surface of the circumferential edge projection part 36). When the buffer member 30 receives the third load F3, the abutting part 36 m, provided on a side surface of the circumferential edge projection part 36, abuts onto the protruding part 16 p, so that deformation in a width direction of the circumferential edge projection part 36 is restricted. Although each of FIGS. 11 and 12 shows an example in which two protruding parts 16 p are provided, a single protruding part 16 p or three or more protruding parts 16 p can be provided.

The deformation restricting unit 18 can also be configured by increasing a friction coefficient μ of the lower surface 30 b of the buffer member 30 (the lower surface of the circumferential edge projection part 36) or the facing surface 16. Increasing the friction coefficient μ restricts the move of the circumferential edge projection part 36, thereby restricting the deformation of the buffer member 30, for example.

The friction coefficient μ can be changed by changing the asperities or the surface roughness of the lower surface of the circumferential edge projection part 36. For example, to change the surface roughness, a mirror finish or embossing can be performed on the lower surface of the circumferential edge projection part 36. The friction coefficient μ can be changed also by attaching a member having a different friction coefficient to a surface of the body part 35. In this embodiment, attaching a low-friction material can decrease the friction coefficient and attaching a high-friction material can increase the friction coefficient μ. Further, the friction coefficient μ can be changed also by applying a material that can change the lubrication properties to a surface of the body part 35.

FIG. 13 is now referred to. The dimension in a width direction of a part of the portion 35 e on the lateral side that is in contact with the facing surface 16 and the dimension in a width direction of a part of the portion 35 j on the medial side that is in contact with the facing surface 16 can be the same or can be different. FIG. 13 is a sectional view, taken along line A-A, of the buffer member 30 of which the widths of the medial side and the lateral side of the body part 35 are different and corresponds to FIG. 6. In cross sectional view of FIG. 13, a dimension Wcj on the medial side of the body part 35 is larger than a dimension Wce on the lateral side of the body part 35. In this example, since the dimension Wcj is larger than the dimension Wce, the contact area between the facing surface 16 and the circumferential edge projection part 36 becomes larger and so does the frictional force, so that the circumferential edge projection part 36 is less likely to move. As a result, lowering of the inner side is restricted, so that the stability can be ensured easily. Considering the load balance between the medial side and the lateral side under high load, the dimension Wce can be larger than the dimension Wcj.

FIG. 14 is now referred to. The friction coefficient μ between the body part 35 and the facing surface 16 can be entirely uniform or can be partially different. When the friction coefficient μ is made partially large, the move and deformation of the relevant part can be made smaller. FIG. 14 is a sectional view, taken along line A-A, of the buffer member 30 of which the friction coefficients μ of the medial side and the lateral side of the body part 35 are different and corresponds to FIG. 6.

In the example shown in FIG. 14, a friction coefficient μj between the portion 35 j on the medial side and the facing surface 16 is larger than a friction coefficient μe between the portion 35 e on the lateral side and the facing surface 16. In this embodiment, when a high load is applied to the medial side during exercise, deformation can be restrained, so that the stability can be easily ensured. Considering the load balance between the medial side and the lateral side under high load, the friction coefficient μe can be made larger than the friction coefficient μj.

There will now be described the features of the shoe 100 according to the first embodiment configured as described above. The shoe 100 according to the first embodiment includes the sole 10, the upper portion 20 provided above the sole 10 to surround the foot insertion part 20 a, and the buffer member 30 accommodated within the foot insertion part 20 a. On the lower surface 30 b of the buffer member 30, there are provided the projection part 32 projecting toward the facing surface 16 that faces the lower surface 30 b, the recess part 34 formed adjacent to the projection part 32 and recessed from the projection part 32 toward the upper portion 20 side, and the circumferential edge projection part 36 projecting, around the recess part 34, toward the facing surface 16 side with respect to the projection part 32. When the buffer member 30 receives a predetermined first load F1, the circumferential edge projection part 36 contacts the facing surface 16 whereas the projection part 32 has no contact with the facing surface 16. When the buffer member 30 receives a predetermined second load F2, which is larger than the first load F1, the circumferential edge projection part 36 and the projection part 32 contact the facing surface 16.

With this configuration, in the case of a low load in which the projection part 32 has no contact with the facing surface 16, the displacement of the buffer member 30 caused by the load can be increased, so that the shoe feels smooth for the foot. Also, in the case of a high load in which the projection part 32 contacts the facing surface 16, the displacement of the buffer member 30 caused by the load can be decreased, so that the stability can be ensured.

The space S1 in a width direction between the peripheral wall surface 30 p of the buffer member 30 and the upper portion 20 is larger than the space S2 in a longitudinal direction between the peripheral wall surface 30 p and the upper portion 20. In this embodiment, since the space S1 in a width direction is larger, the buffer member 30 can be easily inserted into the foot insertion part 20 a.

In a width direction, the recess part 34 intervenes between the projection part 32 and the circumferential edge projection part 36. Extension in a width direction of the buffer member 30 receiving a downward load is larger than extension in a longitudinal direction thereof. In this embodiment, since a received load can be distributed in a width direction, the stability and the comfort can be adjusted.

The deformation restricting unit 18 is provided to restrict a predetermined amount or more of deformation of the buffer member 30. In this embodiment, excessive deformation can be restricted. Also, with the changes at multiple (three) stages, the stability under high load can be further ensured.

The deformation restricting unit 18 is disposed on a part that faces the lower surface 30 b or an outer peripheral side surface of the buffer member 30. In this embodiment, excessive deformation can be restricted, with a simple configuration.

The deformation restricting unit 18 includes the protruding part 16 p protruding from the facing surface 16. In this embodiment, excessive deformation can be restricted, with a simple configuration.

The buffer member 30 includes the body part 35 that includes the circumferential edge projection part 36, and the movable part 33 that includes the projection part 32. The body part 35 has an outer shape extending along the foot insertion part 20 a and includes the accommodation part 37 that accommodates at least part of the movable part 33. When a downward load is applied to the buffer member 30, the movable part 33 moves downward with respect to the body part 35. In this embodiment, since the movable part 33 is provided separately, the movable part 33 can smoothly move downward when a load is applied. Also, since the movable part 33 is provided separately, the components can be manufactured on the respectively suitable conditions.

The accommodation part 37 includes the opening part 37 h provided in a middle part in a width direction of the body part 35. In this embodiment, since the opening part 37 h is provided, the movable part 33 can move downward within the opening part 37 h.

The inner circumferential surface 37 j of the accommodation part 37 is formed into a tapered shape. In this embodiment, by adjusting the tapered shape, displacement caused by a load can be easily adjusted to achieve a desired property.

The outer circumferential surface of the movable part 33 has a shape corresponding to the inner circumferential surface 37 j. In this embodiment, the movable part 33 can move smoothly.

When the buffer member 30 receives the first load F1, the movable part 33 is positioned away upward from the facing surface 16. In this embodiment, under low load, displacement caused by the load can be made larger, thereby improving smoothness for a foot during insertion thereof.

The movable part 33 has a planar shape of an ellipse of which a longitudinal dimension is larger than a width dimension. In this embodiment, since the longitudinal dimension is larger, the load-displacement characteristics can be adjusted in a longitudinally large range.

The hardness of the material of the movable part 33 is different from the hardness of the material of the body part 35. In this embodiment, since each of the body part 35 and the movable part 33 can be formed of a material having suitable hardness, desired load-displacement characteristics can be easily achieved.

The hardness of the material of the body part 35 is different between the portion 35 j on the medial side and the portion 35 e on the lateral side thereof, between which along a width direction the movable part 33 is disposed. In this embodiment, since each of the medial side portion and the lateral side portion can be formed of a material having suitable hardness, desired load-displacement characteristics can be easily achieved.

The area of the body part 35 in contact with the facing surface 16 is different between the portion 35 j on the medial side and the portion 35 e on the lateral side of the body part 35, between which the movable part 33 is disposed. In this embodiment, since each of the areas can be set considering the load balance between the medial side and the lateral side under high load, desired load-displacement characteristics can be easily achieved.

The friction coefficient between the body part 35 and the facing surface 16 is different between the portion 35 j on the medial side and the portion 35 e on the lateral side of the body part 35, between which the movable part 33 is disposed. In this embodiment, since each of the friction coefficients can be set considering the load balance between the medial side and the lateral side under high load to adjust the deformation properties, desired load-displacement characteristics can be easily achieved.

Second Embodiment

With reference to FIGS. 15-20, a configuration of a shoe 200 according to the second embodiment of the present invention will be described. In the drawings and description of the second embodiment, like reference characters denote like or corresponding constituting elements and members in the first embodiment. Repetitive description already provided in the first embodiment will be omitted as appropriate, and configurations different from those in the first embodiment will be intensively described. FIG. 15 is a perspective view that schematically illustrates the shoe 200 according to the second embodiment. FIG. 16 is a side view of the shoe 200. FIG. 17 is a plan view of the shoe 200. FIG. 18 is a sectional view taken along line B-B in FIG. 17. In FIGS. 15 and 16, illustration of the shoe tongue is omitted.

Link Member

The shoe 200 of the present embodiment differs from the shoe 100 of the first embodiment in including a link member 52, and the other configurations are similar to those in the first embodiment. Accordingly, the link member 52 will be intensively described. When the buffer member 30 receives the load F and gets deformed, the space between the upper portion 20 and the instep becomes larger, which may impair the fit. Accordingly, the shoe 200 of the present embodiment includes the link member 52 that deforms, when the buffer member 30 receives the load F and gets deformed, the upper portion 20 in conjunction with the deformation of the buffer member 30.

The link member 52 in the present embodiment includes a sole side part 52 d, extension parts 52 p, and fixed parts 52 f The sole side part 52 d is a portion that intervenes between the sole of the foot and the top surface 30 e of the buffer member 30 and that extends in a substantial width direction. The extension parts 52 p are portions that extend respectively from both ends in a width direction of the top surface 30 e and extend in a substantially vertical direction. The fixed parts 52 f are portions provided respectively at top edges of the extension parts 52 p and fixed to the upper portion 20. The fixed parts 52 f are respectively fixed, by sewing or the like, to regions on both sides in a width direction of the upper portion 20 between which the central opening 20 c is provided. The fixed parts 52 f can be fixed integrally with the upper portion 20 by the grommets 20 h. For example, the sole side part 52 d, extension parts 52 p, and fixed parts 52 f can be integrally formed of a flexible sheet member, such as cloth.

As illustrated in FIG. 17, the link member 52 in the present embodiment is provided at a position other than the wearing opening 20 b of the upper portion 20. Also, the extension parts 52 p of the link member 52 are fixed to the upper portion 20 via the fixed parts 52 f, in front of the wearing opening 20 b. In this embodiment, the buffer member 30 can be easily inserted into the foot insertion part 20 a through the wearing opening 20 b and removed through the wearing opening 20 b.

As illustrated in FIG. 18, the sole side part 52 d is disposed in contact with or closer to the top surface 30 e of the buffer member 30. When the load F is applied from the sole of the foot, downward tension T acts on the extension parts 52 p and the top surface 30 e of the buffer member 30. When the tension T acts on the extension parts 52 p, downward force P acts, in conjunction therewith, on the fixed parts 52 f and the upper portion 20. As a result, the upper portion 20 is drawn downward, moderating the expansion of the space between the upper portion 20 and the instep. In other words, since the link member 52 intervenes between the sole of the foot and the top surface 30 e of the buffer member 30, the upper portion 20 and the link member 52 are lowered together with the buffer member 30. With this mechanism, the upper portion 20 and the buffer member 30 can fit onto the foot.

The link member 52 can include a cylindrical portion or a bag-shaped portion for wrapping the foot, in terms of ensuring support. In this embodiment, when the buffer member 30 is deformed, the upper portion 20 can be certainly drawn downward.

FIGS. 19 and 20 are side views that illustrate other examples of the shape of the link member 52. The link member 52 shown in FIG. 19 differs from the link member 52 shown in FIG. 16 in including a rear portion 52 h extending from the midfoot portion toward the rear side, and the other configurations are similar to those in the link member 52 shown in FIG. 16. The rear portion 52 h can extend to a region corresponding to the heel. An upper portion part of the rear portion 52 h is fixed to the inner side of the upper portion 20 by sewing or the like. In this example, a rear end part of the rear portion 52 h is formed into a cylindrical shape.

The link member 52 shown in the example of FIG. 20 differs from the link member 52 shown in FIG. 16 in including a front portion 52 j extending from the midfoot portion toward the front side, and the other configurations are similar to those in the link member 52 shown in FIG. 16. The front portion 52 j can extend to a region corresponding to the toe. The front portion 52 j can be formed into a bag shape or a cylindrical shape for wrapping the forefoot portion of the inserted foot. In this example, the front portion 52 j is formed into a bag shape of which the front side is closed. An upper portion part of the front portion 52 j can be fixed to the inner side of the upper portion 20 but is not fixed in this example.

The shoe 200 of the present embodiment achieves the same effects as the first embodiment, and, in addition, since the upper portion 20 is drawn downward in conjunction with deformation of the buffer member 30, the space between the upper portion 20 and the instep does not become excessively large under high load, which improves the fit. Also, the comfort under low load can be maintained.

Exemplary embodiments of the present invention have been described in detail. Each of the abovementioned embodiments merely describes a specific example for carrying out the present invention. The embodiments are not intended to limit the technical scope of the present invention, and various design modifications, including changes, addition, and deletion of constituting elements, can be made to the embodiments without departing from the scope of ideas of the invention defined in the claims. In the aforementioned embodiments, matters to which design modifications can be made are described with the expression of “of the embodiment”, “in the embodiment”, or the like. However, it is not unallowable to make a design modification to a matter without such expression. Also, the hatching provided in the drawings does not limit the materials of the objects with the hatching.

Modifications

In the following, modifications will be described. In the drawings and description of the modifications, like reference characters denote like or corresponding constituting elements and members in the embodiments. Repetitive description already provided in the embodiments will be omitted as appropriate, and configurations different from those in the embodiments will be intensively described.

First Modification

Although the first embodiment describes an example in which the buffer member 30 includes a single movable part 33, the present invention is not limited thereto. The buffer member 30 can include multiple movable parts 33. FIG. 21 is a plan view of the buffer member 30 according to the first modification and corresponds to FIG. 2. In the buffer member 30 shown in FIG. 21, multiple movable parts 33 are provided to be spaced away from each other in a longitudinal direction. In the buffer member 30 of this example, a movable part 33 of oval shape in plan view is provided in each of a portion corresponding to the heel and a portion corresponding to the toe. The positions of the movable parts 33 are not limited thereto, and each movable part 33 can be arranged in a part where the load F is more likely to be applied. Considering the load balance between the front side and the rear side under high load, a movable part 33 can be provided in one of the portion corresponding to the heel and the portion corresponding to the toe.

Also, the size or deformation properties of each of the movable parts 33 in the forefoot portion and the rearfoot portion can be adjusted. In this embodiment, when the rearfoot portion is easily deformable while the forefoot portion is highly repulsive, for example, the rearfoot portion can be given the cushioning properties while the forefoot portion can be given the repulsive force during running or the like, thereby providing a shoe suitable for runners who land on their heels. Also, by providing multiple movable parts 33, the sizes or deformation properties of the movable parts 33 can be changed based on the landing pattern of each wearer.

Other Modifications

Although the first embodiment describes an example in which the protruding part 16 p is provided as the deformation restricting unit 18, the present invention is not limited thereto. For example, instead of the protruding part 16 p, a sheet member can be provided between the body part 35 and the movable part 33 to increase the frictional force therebetween. Also, onto a surface of one of the body part 35 and the movable part 33, a tape having a high friction coefficient can be attached, for example.

The first embodiment describes an example in which the movable part 33 has a planar shape of an ellipse. However, the present invention is not limited thereto, and the movable part 33 can have various shapes depending on a desired property. In the following, first through fourth exemplary shapes of the movable part 33 will be described. FIGS. 22-25 are plan views that respectively illustrate the first through fourth exemplary shapes of the buffer member 30 and that each correspond to FIG. 2. In the buffer member 30 having the first exemplary shape illustrated in FIG. 22, the movable part 33 has a planar shape that longitudinally extends from the portion corresponding to the heel to a portion corresponding to the midfoot portion. In this embodiment, when the portion corresponding to the heel is made easily deformable while the midfoot portion is made highly repulsive, for example, the portion corresponding to the heel can be given the cushioning properties while the midfoot portion can be given the repulsive force during running or the like, thereby providing a shoe suitable for runners who land on their heels. Also, by providing the movable part 33 having such a shape, the size or deformation properties of the movable part 33 can be changed based on the landing pattern of each wearer.

In the buffer member 30 having the second exemplary shape illustrated in FIG. 23, the movable part 33 has a planar shape that longitudinally extends from the portion corresponding to the heel to the portion corresponding to the toe. In this way, the movable part 33 can have various longitudinal lengths from part of the buffer member 30 to the entire region thereof, depending on a desired property. Also, when the movable part 33 having such a shape is provided, by making the movable part 33 softer when the comfort, not the exercise use, is considered important, a shoe of which the amount of deformation is large can be provided.

In the buffer member 30 having the third exemplary shape illustrated in FIG. 24, the movable part 33 has a planar shape that longitudinally extends from the portion corresponding to the heel to the portion corresponding to the midfoot portion. In this example, the movable part 33 has a shape in which the portion corresponding to the midfoot portion is located closer to one side in a width direction (such as the lateral side). When the movable part 33 having such a shape is provided, by making the movable part 33 softer and making the body part 35 harder, a shoe that is highly effective in restraining pronation can be provided.

In the buffer member 30 having the fourth exemplary shape illustrated in FIG. 25, the movable part 33 has a planar shape of a polygon. In this example, the movable part 33 has a planar shape of a hexagon that extends from the portion corresponding to the midfoot portion to the portion corresponding to the toe. When the movable part 33 having such a shape is provided, the shoe can achieve more easily the properties suitable for runners who land on their forefoot portions. Having a polygonal shape is not essential, and each angular part can be formed into a curved shape.

Although the first embodiment describes an example in which the projection part 32 and the circumferential edge projection part 36 are formed separately, the present invention is not limited thereto. The projection part 32 and the circumferential edge projection part 36 can be formed integrally. FIGS. 26 and 27 are longitudinal sectional views, taken along line A-A, of the buffer member 30 in which the projection part 32 and the circumferential edge projection part 36 are formed integrally, which correspond to FIGS. 6 and 7. FIG. 26 shows the buffer member 30 in a no-load state, and FIG. 27 shows the buffer member 30 receiving the second load F2.

As illustrated in FIG. 26, the contour of a cross section on the facing surface 16 side of the projection part 32 located between portions of the recess part 34 forms a substantial M-shape. The circumferential edge projection part 36 is in contact with the facing surface 16 at two or more positions with the projection part 32 located in between. In cross sectional view of FIG. 26, the total dimensions of regions in the circumferential edge projection part 36 in contact with the facing surface 16 in a no-load state can be 30% or more of a width dimension Wa of the entire buffer member 30. More specifically, the sum of the dimension Wce in a width direction of the region in contact with the facing surface 16 on the lateral side of the circumferential edge projection part 36 and the dimension Wcj in a width direction of the region in contact with the facing surface 16 on the medial side of the circumferential edge projection part 36 can be 30% or more of the width dimension Wa. Also, the sum of the dimension Wce and the dimension Wcj can be 70% or less of the width dimension Wa.

Also, in cross sectional view of FIG. 26, a vertical distance Hp between a portion 32 p of the projection part 32, which is located vertically closest to the facing surface 16, and the facing surface 16 can be 2 mm or greater in a no-load state. Also, the vertical distance Hp can be 10 mm or less.

Also, in cross sectional view of FIG. 26, a vertical distance Hd between a portion 34 d of the recess part 34, which is located vertically farthest from the facing surface 16, and the portion 32 p can be 1 mm or greater in a no-load state. Also, the vertical distance Hd can be 13 mm or less.

Also, in cross sectional view of FIG. 26, a vertical thickness Ha of the buffer member 30 along a vertical line that passes through the portion 32 p can be 10 mm or greater in a no-load state. Also, the vertical thickness Ha can be 30 mm or less.

As illustrated in FIG. 27, when the buffer member 30 receives the second load F2, the projection part 32 contacts the facing surface 16, as is the case in the first embodiment.

Although the second embodiment describes an example in which the sole side part 52 d intervenes between the sole of the foot and the top surface 30 e of the buffer member 30, the present invention is not limited thereto. FIG. 28 is a sectional view of a shoe 300 according to a modification taken along line B-B and corresponds to FIG. 18. The present modification differs from the second embodiment in that the sole side part 52 d intervenes between the buffer member 30 and the sole 10, and the other configurations are similar to those in the second embodiment. In the present modification, the extension parts 52 p extend respectively from both ends in a width direction of the sole side part 52 d. According to the present modification, similarly to the second embodiment, the upper portion 20 and the link member 52 are lowered together with the buffer member 30, so that the upper portion 20 and the buffer member 30 can fit onto the foot.

Each of the abovementioned modifications provides functions and effects similar to those of the aforementioned embodiments.

Optional combinations of the aforementioned embodiments and modifications can also be practiced as additional embodiments of the present invention. Such an additional embodiment made by combination has the effect of each of the combined embodiments and modifications.

Embodiments of the present invention relate to a buffer member of a shoe and is applicable to a shoe. 

1. A shoe, comprising: a sole; an upper portion disposed above the sole and configured to surround a foot insertion part; and a buffer member including a lower surface and accommodated within the foot insertion part, the lower surface of the buffer member including a projection part projecting toward a facing surface that faces the lower surface, a recess part adjacent to the projection part and recessed from the projection part toward the upper portion, and a circumferential edge projection part projecting, around the recess part, toward the facing surface side with respect to the projection part, when the buffer member receives a predetermined first load, the circumferential edge projection part contacts the facing surface whereas the projection part has no contact with the facing surface, and when the buffer member receives a predetermined second load, which is larger than the first load, the circumferential edge projection part and the projection part contact the facing surface.
 2. The shoe according to claim 1, wherein a space in a width direction between a peripheral wall surface of the buffer member and the upper portion is larger than a space in a longitudinal direction between the peripheral wall surface and the upper portion.
 3. The shoe according to claim 1, wherein the recess part intervenes between the projection part and the circumferential edge projection part in a width direction, and extension in a width direction of the buffer member receiving a downward load is larger than extension in a longitudinal direction thereof.
 4. The shoe according to claim 1, further comprising a deformation restrictor configured to restrict a predetermined amount or more of deformation of the buffer member.
 5. The shoe according to claim 4, wherein the deformation restrictor is provided on a part that faces the lower surface or an outer peripheral side surface of the buffer member.
 6. The shoe according to claim 5, wherein the deformation restrictor comprises a protruding part protruding from the facing surface.
 7. The shoe according to claim 1, wherein the buffer member comprises a body part including the circumferential edge projection part, and a movable part including the projection part, the body part has an outer shape extending along the foot insertion part and includes an accommodation part configured to accommodate at least part of the movable part, and when a downward load is applied to the buffer member, the movable part moves downward with respect to the body part.
 8. The shoe according to claim 7, wherein the accommodation part includes an opening part disposed in a middle part in a width direction of the body part.
 9. The shoe according to claim 8, wherein an inner circumferential surface of the accommodation part has a tapered shape.
 10. The shoe according to claim 9, wherein an outer circumferential surface of the movable part extends along the inner circumferential surface.
 11. The shoe according to claim 7, wherein, when the buffer member receives the first load, the movable part is positioned away upward from the facing surface.
 12. The shoe according to claim 7, wherein the movable part is one of a plurality of movable parts provided with a space in between along a longitudinal direction.
 13. The shoe according to claim 7, wherein the movable part has a planar shape of an ellipse of which a longitudinal dimension is larger than a width dimension.
 14. The shoe according to claim 7, wherein a hardness of a material of the movable part is different from a hardness of a material of the body part.
 15. The shoe according to claim 7, wherein a hardness of a material of the body part is different between a medial side portion and a lateral side portion thereof, between which along a width direction the movable part is disposed.
 16. The shoe according to claim 7, wherein an area of the body part in contact with the facing surface is different between a medial side portion and a lateral side portion of the body part, between which the movable part is disposed.
 17. The shoe according to claim 7, wherein a friction coefficient between the body part and the facing surface is different between a medial side portion and a lateral side portion of the body part, between which the movable part is disposed.
 18. The shoe according to any one of claim 1, further comprising a link member configured to draw the upper portion downward when the buffer member receives a downward load.
 19. The shoe according to claim 18, wherein the link member is fixed to a position other than a wearing opening of the upper portion.
 20. The shoe according to claim 19, wherein the link member comprises a sole side part positioned on a top surface side of the buffer member, and an extension part that extends upward from each of both ends in a width direction of the sole side part.
 21. The shoe according claim 18, wherein the link member includes a cylindrical portion or a bag-shaped portion that is capable of wrapping a foot. 